Hemolytic Anemias

Question 1

hemolytic anemia

Answer 1

intravascular rupture of RBC or increased uptake by phagocytes

Question 2

plasma

Answer 2

liquid portion of blood

Question 3

serum

Answer 3

liquid left over if you let blood clot

CANNOT asses blood coagulation

Question 4

hemolytic anemia lab findings

Answer 4

1. free hemoglobin increased
2. LDH increased
3. haptoglobin reduced (infection/inflammation can artificially increase)
4. unconjugated bilirubin

Question 5

spherocytosis

Answer 5

genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test

Question 6

hemoglobinopathies

Answer 6

genetic hemolytic anemia: crystallization of hemoglobin
missense mutation
Hgb S, HgB C, HgB SC, Hgb E
Dx: hemoglobin electrophoresis

Question 7

pyruvate kinase deficiency

Answer 7

genetic hemolytic anemia
decreases in ATP inhibits the Na/K ATPase, sodium leaks into the cell, water follows and cell bursts
polychromes counted as reticulocytes
Dx: enzyme activity test

Question 8

hereditary spherocytosis

Answer 8

genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test

Question 9

pyropoikilocytosis

Answer 9

genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test

Question 10

hereditary eliptocytosis

Answer 10

genetic hemolytic anemia
defects membrane anchors, spectrin, or ankyrin
Dx: osmotic fragility test

Question 11

G6PD deficiency

Answer 11

genetic hemolytic anemia
X-linked
defect in anti-oxidant system: can’t produce NADPH via the pentose phosphate pathway to reduce glutathione needed to reduce peroxide
Heinz bodies, methemoglobinemia
induced by: fava beans, bactrim (sulfamethoxazole), anti-malarials, lots of drugs
Dx: enzyme activity

Question 12

methemoglobinemia

Answer 12

extensive oxidation of heme iron (now Fe3+)

Question 13

Drugs that should be avoided in G6PD deficiency

Answer 13

1. dapsone
2. methylthioninium chloride (methylene blue)
3. nitrofurantoin
4. phenazopyridine
5. primaquine
6. rasburicae
7. tolonium chloride (toluidine blue)
   * Many used to treat malaria and G6PD is prevalent in same region

Question 14

paroxysmal nocturnal hemoglobinuria

Answer 14

neoplastic/ acquired genetic
unimpaired complement fixation: MAC destroys RBC (no phosphotidylinosital glycan: no DAF)
Dx: flow cytometry
Tx: allogenic bone marrow transplant and ecluzimab

Question 15

malaria

Answer 15

infectious hemolytic anemia
intracellular protozoal parasite
travel to tropical/ subtropical areas: anopheles mosquito
high fever, dark urine, jaundice
thick smear needed if parasite load isn’t high

Question 16

merozoites

Answer 16

early form of plasmodium

Question 17

plasmodium falciparum

Answer 17

parasite that causes malaria
most lethal form
Africa

Question 18

plasmodium vivax

Answer 18

parasite that causes malaria

Caribbean

Question 19

babesia

Answer 19

infectious hemolytic anemia
protozoal intracellulair parasite
ticks
NE U.S.

Question 20

Bartonella baciliformis

Answer 20

infectious hemolytic anemia (sever in acute phase)
rash in chronic phase
fever, splenomegaly
sand flies
northern Andes (Peru, Ecuador, Colombia)
other names: Carrions disease, Oroya fever

Question 21

C. perfringens (welchii)

Answer 21

infectious hemolytic anemia
normal skin flora
gas gangrene or sever anemia
trauma, septic abortions, rare complication of cholecystitis, or cancer

Question 22

warm autoimmune hemolytic anemia

Answer 22

Ab against RBC antigens: cleared by phagocytes
extravascular and intravascular hemolysis
microspherocytes, nucleated red cells, basophilic stippling, polychromasia, hemolysis lab tests
DAT positive at 37 F for complement and Ab
NO blasts or myelocytes
Associated with: lymphoma, malignancies, autoimmune
Tx: steroids, splenectomy
Prognosis: poor

Question 23

extravascular hemolysis

Answer 23

macrophages clear RBC marked with C3b

Question 24

intravascular hemolysis

Answer 24

MAC complex destroy RBCs

Question 25

direct antiglobulin test (DAT)

Answer 25

direct Coombs test

Question 26

Why would you add exogenous RBCs to a DAT?

Answer 26

RBC with Ab bound may get lysed/cleared rapidly and undetectable to DAT

Question 27

What is a problem with DAT?

Answer 27

nonspecific: up to 8% of hospitalized patients have a positive DAT

Question 28

cold autoimmune hemolytic anemia

Answer 28

cold agglutinins with broad thermal amplitude (up to 37 F) or high concentration: IgM Ab raynaud's phenomenon, hemolysis by serum tests, RBC agglutination, polychromasia, basophilic stippling, nucleated RBC Clumping: may get inaccurately low red cell count and hematocrit: have to warm up for accurate count DAT: + at room temp for IgM, + at 37 F for C3 Ab screen: + at room temp, - at 37 F NO blasts or myleocytes associated with: viral syndromes, Mycoplasma Tx: steroids, splenectomy Prognosis: chronic, seasonal

Question 29

thrombotic thrombocytopenia purpura (TTP)

Answer 29

Ab against adamTS13 thromboses, thrombocytopenia, hemorrhage microangiopathic hemolytic anemia: scistocytes fever, renal failure, CNS symptoms in absence of sepsis Tx: plasmapheresis

Question 30

AdamTS13

Answer 30

cleaves vWF to the appropriate size

Question 31

vWF

Answer 31

link platelets to damaged endothelium

Question 32

blood transfusion: major antigen mismatch

Answer 32

acute hemolysis immediately or within hours

Question 33

blood transfusion: minor antigen mismatch

Answer 33

delayed hemolytic reactions (1-7 days)